So, i realized Vorwerk robovacs have bigger side brush than on Neatos, so i thought to give it a shot and ordered Vorwerk brush from China.

Each brush is about 1cm longer than Neatos brush. Neatos side brush shaft is couple mm thicker than Vorwerk. But Vorwerks side brush has different height, so...

Pretty simple. Unscrew the Neatos side brush shafts Torx screw (no need to open the robot), find a new, but longer screw and use two nuts that fit to Vorwerks side brush mounting. Then screw the new screw/nut assembly to Neatos side brush shaft and voila, you can use Vorwerk side brush on Neato, and revert it back to OEM if you want.

Cleans edges on hard floors much more better than Neatos brush, but on carpet it strugles because of the belt drive.